The primary objectives of an enclosed guard tower are to: protect the guards from the environment; provide maximum observational visibility; and allow quick access and egress for guards in emergency situations. If the tower is used on the beach for lifeguards, it should be light weight for easy seasonal transport to and from the beach location. It should also be small so that it will not interfere with the use of the beach, rugged in construction, pleasing in appearance and low in cost. When the tower is stored during the off season, a minimum of effort to convert from a storage mode to an operational mode is also desirable.
Specifically, if the enclosed tower is to provide full protection from the environments during operation and storage, as well as quick exit and egress, it must include at least one conveniently operated door to the enclosure. The door must meet this quick exit/egress requirement without impeding the guard's visibility during egress/exit.
Most of the current lifeguard towers may do one of these objectives well, but other objectives poorly or not at all. Open towers provide maximum visibility, but little or no protection from the environment. All glass enclosures may not provide sufficient protection form the environment, especially shade from the sun. Normal enclosed structures having a structure to support a roof (and vertical walls and windows) may limit visibility. A major drawback of this type of vertical wall construction is the glare and reflection from the glass windows during certain periods of the day. Roof support structure may also detract from quick access and egress objectives.
One approach is to provide an enclosure having angled (nonvertical), windows and an overhanging roof. The angled window design provides that the top of the window is outboard of the lower part of the window. This positioning reflects some of the low angle glare when the sun (or other source of the glare) is low in the sky or proximate to the horizon, but allows maximum visibility in these low angle directions. High angle sources of glare are totally eliminated by the overhanging roof.
This approach resolves many of the visibility and enclosure needs, but creates a difficult structure to provide quick access/egress without compromising visibility. Normal vertical doors would require a vertical door jamb and triangular wall sections to adapt from the vertical door to the angled window frame structure. The door jamb and triangular wall section structures tend to be unappealing and awkward, also limiting access and use. Most importantly for this application, these wall structures impede visibility at a critical time.
Visibility is most necessary from when the guard first observes an emergency and exits the enclosure to react to emergency. The lifeguard, for example, needs to maintain visual contact with the drowning victim or other emergency during this critical exiting and reaction time. The vertical door jamb and structural triangular wall and window frame adapter sections create a blind spot, necessarily impeding this critical visibility just as the guard exits the enclosure.
These prior approaches have other many limitations. These are primarily related to the incompatibility of the slanted window and window frame construction with the vertical doors. The vertical door provides little or no support of the roof because of the incompatibility. The structure at the door jamb must be structurally reinforced to support the roof at this point. The multiplicity of elements required to accomplish the adaption to the slanted window and window frame design and roof support, creates added cost, weight and space. This multiplicity of elements, weight and space particularly detract from the reliability of the structure.
Although a slanted door could be used, opening the door would be limited to inward directions unless a step down is provided. This changed direction of opening or step down would distract and delay the exit of the guard during these critical emergency periods. A slanted portion of a vertically hinged door could be used, hinged attachment could only be placed on a vertical portion of the door, resulting in problems similar to the full vertical door. In addition, provision (space and structural support) for the slanted door portion would have to be made when the door was open. Sealing the slanted portion against the environment presents still other problems.
Another problem with prior art construction is the support of shutters. Shutters are provided to protect the windows and doors from extreme storms or other strong environmental forces. The prior art vertical door jamb, triangular adaptor structure must also interface and provide support for the shutters, if included.
None of the prior art guard-like towers having slanted window and overhanging roof construction known to the applicant avoids these vertical door and full or partial triangular adaptor obstruction or slanted door problems. What is needed is a door which can be vertically hinged to open outward, securely hinged along the entire height, but adapt to a slanted window and window frame structure.